Nov 11, 2009
GWG members -
The value and importance of metadata is that it enables discovery of information and is a key enabler of data and system interoperability. Metadata is data about data that describes the content and the appropriate use of a data resource. The proper use of metadata is critical, which if not implemented well, would prohibit or significantly limit a consumer's proper use and exploitation of that resource, or even the awareness of that resource in the first place.
Metadata is becoming even more critical as the volumes of archived data and imagery continue to grow to enormous volumes such that humans could not possibly access and evaluate all this data. Without good metadata, a consumer could not search and retrieve the data that contains the characteristics and content necessary to support a required mission. Metadata instills data accountability and limits data liability. The timely capture of metadata is also fundamental to the quality of the data resource as a whole.
The NSG Metadata Foundation (NMF) document, attached, is a single reference standard, defining the conceptual schema for specifying geospatial metadata in and for the NSG. The companion NSG Metadata Implementation Specification (NMIS) is under development and will define the methods for specifying and encoding geospatial metadata in the NSG.
The NMF/NMIS is the result of the convergence of two parallel developments; the NSG Geospatial Intelligence Core Metadata Profile (NGCMP) and the GEOINT Structure Implementation Profile (GSIP) development, and is intended to define and specify geospatial metadata for the National Geospatial-Intelligence Agency (NGA) and its customers, and at a higher and wider level, the National System for Geospatial Intelligence (NSG). The main goal of the NMF and NMIS is to support the data discovery and interoperability needs of the NSG in both today's and tomorrow's systems.
As briefed at the October 14th, 2008 GWG MFG meeting, this version of the NMF (0.8g) has changed significantly from the previous version (0.8f). The NMF conceptual model is now a direct Profile of ISO 19115:2003/Cor 1:2006, and there are no additional Profiles or Modules present in the NMF. The Coverage, Sensor and Services modules have been removed in order to get the base document out, and entered into the DISR. Those modules will follow along shortly, as time and resources permit.
The only extensions that remain are the additional security elements that are required for CAPCO.
The UML models from ISO 19115 have been profiled, according to the requirements first documented in the NGCMP document. There are tables in Section 4 of the NMF that spell out those requirements, and how they are fulfilled by the UML classes and elements of ISO 19115.
The document is in a Draft state, and comments are welcomed and encouraged.
Under the Geospatial Intelligence Standards Working Group (GWG), the National Geospatial-Intelligence Agency (NGA) leads the Metadata Focus Group (MFG) which serves as the NSG community-wide forum to leverage NSG resources to conduct and coordinate pertinent metadata standardization efforts. It is within this Metadata Focus Group that the NMF and NMIS were developed and maintained.
Questions or comments on the NMD-NMIS should be sent to:
Gary Hall (NGA/NCGIS): , 703-961-8090
Shawn Silkensen (EE support): , 703-460-3406